There is a technique of displaying images in a display device in which a display functional layer such as a liquid crystal layer, an organic EL (Electro-Luminescence) layer, or a fluorescent layer is disposed between a pair of substrates disposed to be opposed to each other. For example, Japanese Patent Application Laid-Open Publication No. 2012-83597 (Patent Document 1) describes a liquid crystal display device using a glass substrate made of strengthened glass. Also, Japanese Patent Application Laid-Open Publication No. H9-80405 (Patent Document 2) describes a liquid crystal display device using metal foil which is formed in a lattice-like shape by etching or electroplating and a glass substrate integrally formed by covering a surface of the metal foil. Further, Japanese Patent Application Laid-Open Publication No. H4-242720 (Patent Document 3) describes a technique in which substrates having mutually different linear expansion coefficients are overlapped with each other in a pressurized state with an ultraviolet curable resin interposed therebetween, a part of the ultraviolet curable resin is irradiated with ultraviolet rays to temporarily fix the substrates, and the temporarily fixed substrates are then irradiated with ultraviolet rays to complete the curing.